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Achieving NetZero: Leakage reduction = carbon reduction

Achieving NetZero: Leakage reduction = carbon reduction

By Stuart White, Leakage Services Manager Black & Veatch Europe

Water is the first industrial sector in the UK to commit to a carbon zero future by 2030. In the nearer term water companies in England and Wales need to achieve a 16 percent cut in leakage by 2025. Historically leakage reduction has not been considered as a viable carbon reduction tool. With the combination of NetZero commitments and AMP7 leakage targets, however, this may be about to change.

Electricity generation is a major source of carbon emissions. Water companies are major consumers of electricity. The UK’s water industry is estimated to consume three percent of the electricity the country produces, and is responsible for between 0.8 and one percent of the UK’s greenhouse gas emissions annually. In 2019, UK net emissions of carbon dioxide were provisionally estimated to be 351.5 million tonnes, according to the Department of Business, Energy and Industrial Strategy. This would place the water industry’s emissions at between 2.8 and 3.5 million tonnes of carbon dioxide during that period.

Pumping potable water around the supply network accounts for the largest proportion of water companies’ energy needs. A 2019 study of water companies’ electricity consumption1 found water networks accounted for 33 percent of one company’s total energy demand, with water treatment accounting for a further 24 percent. These figures are broadly representative of UK water companies as a whole. For water supply activities it is estimated, by UKWIR2 that 65 percent of energy consumption derives from distribution and 10 percent from water treatment.

The water/energy/carbon nexus

If a water company reduces the amount of water it is treating and putting into supply the company will, in turn, reduce the amount of energy it is consuming; leading to a corresponding drop in the water company’s operational greenhouse gas emissions. It is possible to reduce the amount of water being treated and put into supply if the company reduces the amount of water being lost, between the treatment works and customers’ taps, from the distribution network.

The effects of leakage on energy consumption can be twofold. In addition to increasing the volume of water it is necessary to treat and pump through the network, leakage can also lead to pressure loss; which means pumping systems must work harder – consuming more power in the process – to maintain the level of pressure required.

As a result, when leakage levels are high, there is potential for leakage reduction to play a role as part of an integrated strategy to achieve NetZero carbon emissions. And leakage levels are high.

In the about 23 percent of the water put into public supply is lost currently through leakage. In England and Wales the figure is about 20 percent. The 2019 energy consumption study cited previously noted that leakage could possibly explain the energy intensiveness of Thames Water’s system.

Gather the data

Data on the amount of energy savings leakage reduction programmes can achieve is limited. A 2010 UKWIR2 study estimated the potential for energy savings from leakage reduction to be up to 38 percent, with the caveat that this is likely to vary considerably depending on companies’ leakage reduction strategies. CIWEM’s 2013 sustainability report A Blueprint for Carbon Emissions Reduction in The UK Water Industry observed, “The potential for pressure management to reduce energy consumption may be being underestimated.”

With a number of provisos, a 2017 American Water Works Association Journal article calculated an average water treatment energy consumption of 2,510 kilowatt/hours per million gallons. If the amount of water being treated can be cut by circa 20 percent – i.e. the average amount of water being lost to leakage – the energy saving, and corresponding cut in carbon emissions, is not insignificant.

The lack of data about leakage reduction’s potential in cutting power consumption, and by extension role in a carbon reduction strategy, speaks directly to one of the changes necessary to improve leakage performance. Historically leakage has been something of a poor relation to major captial programmes. The default response, until recently, has been reactive find-and-fix.

This is no longer sufficient. Find-and-fix alone will not achieve a 16 percent cut in leakage by 2025. Find-and-fix cannot meet the National Infrastructure Commission’s call for a 50 percent leakage reduction by 2050. Success lies in transitioning to strategic network management, part of a data-driven preventative maintenance asset management plan – supporting the entire infrastructure lifecycle - and aligned with sustainability and carbon reduction goals.

Digital transformation of network management

Under pinning the transition to strategic network management is digital transformation. Firstly this will help provide the data necessary to develop a clear understanding of the network’s constituent parts, how they perform individually, and how they interact collectively. Secondly digital transformation will help turn the data into meaningful information that can shape preventative maintenance asset management planning.

The most effective digital transition is founded not just on digital tools and data, but on the deep institutional knowledge of people who understand the network across the infrastructure lifecycle. Sensors, monitoring and analytics are of limited use without the insights of the people who are intimate with how networks are designed, built and behave.

Plug-and-play software systems generate data; but expertise from a cross-section of water engineering disciplines will be necessary to interpret the data patterns and recognise what failure and optimum performance look like. Digital solutions are incomplete unless embedded directly into the engineering solution. Failure to recognise this increases the risk of plug-and-play assets that are not fully integrated into the network management system.

Central to strategic network management is knowing what assets are out there: their history, location and condition. This requires detailed information: pipe size, type and age; hydraulic properties i.e. velocity, pressure head, frictional losses, etc. Most water companies have this information in pockets, but there can be gaps. Strategic network management requires a complete picture. A significant amount of clean data is required to determine optimum performance and before anomalies can be detected with sufficient confidence. Because there is a cost to capturing, storing and accessing each item of data, it is vital to define the data that best supports strategic network management – and focus on ensuring that data is of sufficient quality to deliver the desired outcomes.

Creating a live central database – by combining digitisation of asset records with near-time reporting from sensors and remote surveys – is vital. This will help foster an understanding of which parts of the network are at greatest risk of failure.

Understanding distributed infrastructure

These steps are fundamental for a digitally-enabled network management approach to reducing leakage and carbon emissions. Generating greater insight into how assets are operated and performing enables assessment of network health, which can inform the implementation of proactive interventions while expediting the location and resolution of leakage within the network.

One such solution applying this approach is provided by Black & Veatch, where a District Metered Area (DMA) Health Index provides water companies with the foundation for a data and insight driven strategy to understand how and where to intervene proactively to reduce leakage and carbon impact most effectively.

Data from the network can be augmented with geospatial data to provide a more complete understanding of the network and the factors that increase the risk of failure. Satellite surveys, for example, can provide information about ground movement and changes in soil density and moisture; vegetation – identifying tree species with potentially destructive root systems; and land use – activities such as construction which may pose a risk to buried assets. All of these factors are likely to have changed since the network was laid; so historic asset information can be updated in an ongoing basis, affording a more complete picture of the infrastructure lifecycle.

Geospatial data will also help develop insights into network criticality, i.e. which elements of the network – should they fail – will have the greatest impact. The data can include information such as pipelines’ proximity to vital resources such as hospitals and schools; and critical infrastructure like power stations, substations; and major transport routes. This will help prioritise where resources to prevent bursts should be focussed.

With this level of network understanding the water company can develop Failure Modes Effects and Criticality Analysis (FMECA), which forms the basis of condition-based network maintenance and leakage reduction programmes. The approach ensures networks are optimised, and leakage reduced, in line with a cost and risk profile that meets a water company's business, sustainability and regulatory goals.

Adopting a strategic network management approach will enable leakage reduction programmes to make a meaningful contribution to an integrated carbon reduction strategy, as well as ensuring the most ambitious leakage programme in 20 years can be delivered.


  1. An Analysis of Electricity Consumption Patterns in the Water and Wastewater Sectors in South East England, UK
    Aman Majid, Iliana Cardenes, Conrad Zorn, Tom Russell, Keith Colquhoun, René Bañares-Alcantara, and Jim W. Hall
  2. Energy Efficiency in the Water Industry: A Compendium of Best Practices and Case Studies.
    Brandt, Middleton & Wang.

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